Deffinately new axles. Go to this site:
http://www.driveshaftshop.com/item135637.ctlg
E-mail them... they also offer an axle that's good for up to 750hp. The stock one will snap for sure after a couple runs
As for the LSD:
http://www.quaifeamerica.com/differentials/diffs.htm
http://www.quaifeamerica.com/differe.../diff_apps.htm
That is the best for our cars, in my oppinion.
As for getting 500hp... Good luck! Let me know what you use if you get that! You'll need a HUGE turbo and deffinately some cams (which I didn't see in your mods to the head)... Crower Stage II is what I'm looking at right now.
I started a thread a while back about what's needed to support 500+ hp in a 420A equipped Eclipse... Check that out.
Hope this helps. Feel free to mail me. L8er!
:
: